This invention relates to the coding and decoding of binary and non-binary digital sequences. More specifically it provides novel error-correcting methods and apparatus that allow to correct errors experienced during the transmission of signals.
Digital signals such as binary and non-binary digital sequences are used in the transmission of information. Disturbances of the signals during transmission can cause errors is such a way that the detected signal is different from the transmitted signal. Error-detecting and error correcting codes that address the issue of transmission errors are well known.
A known method to create error correcting codes is by the use of convolutional coding in the encoding process and Viterbi decoding of the signal after reception of the signal. Different methods exist to decode convolutionally coded signals.
The current methods to decode convolutionally coded messages require tracing the many different ways that a current state of the code can be reached in so called Trellis diagrams. These methods can become quite complicated. Hence simpler methods and apparatus to detect and correct errors in a received sequence are required. Most convolutional encoding and decoding techniques apply to binary signals. Hence methods and apparatus to convolutionally encode and decode non-binary signals are required.